In the title compound, C(9)H(11)NOS, the phenyl ring and formamide unit make a dihedral angle of 23.93 (14)°, whereas the (methyl-sulfan-yl)methyl group is oriented at a dihedral angle of 61.31 (8)° with respect to the phenyl ring. There are inter-molecular N-H⋯O hydrogen bonds, forming C(4) chains along the [010] direction. These polymeric chains are linked by C-H⋯O hydrogen bonds to form polymeric sheets in the (110) plane.